1. Field of the Invention
The present invention relates to methods and apparatus for manufacturing flanges for pipe and the like.
2. Description of the Prior Art
There are numerous operations that require the cutting of pipe to length and the joinder of a flange to the ends of the pipes so that the pipe can be joined to an adjacent pipe length. The flanges required for such operations come in many sizes and thicknesses, depending upon the particular application and the restrictions imposed in terms of pressure developed in the pipe and so forth.
One prior art method for manufacturing flanges utilizes common rectangular bar stock which is bent about one short edge thereof in successive bends in a three-roller system. Machines of this type may be either hand operated, or alternatively, may take the form of rather complex machines which serve a similar purpose. See, for example, U.S. Pat. Nos. 2,394,193 to McCabe; and see, 2,498,686 to Johnson, as well as 2,255,867 to Wisckol.
One of the difficulties of prior art flange making machines is that the resulting flange often is not planar because the bending operation results in a "bowing" of the bent bar stock. This results in low yield and high wastage with respect to the raw materials used in the bending process.
Other prior art patents of interest include the following: U.S. Pat. Nos. 3,920,174 to Lanborn; and 2,717,072 to Andrews, et al. In U.S. Pat. No. 2,748,924, McIlvried discloses a draw block mechanism designed for the drawing of metal tubing and the like.